Assessing the quality of institutions’ rankings obtained through multilevel linear regression models

The aim of this paper is to assess the quality of the ranking of institutions obtained with multilevel techniques in presence of different model misspecifications and data structures. Through a Monte Carlo simulation study, we find that it is quite hard to obtain a reliable ranking of the whole effectiveness distribution while, under various experimental conditions, it is possible to identify institutions with extreme performances. Ranking quality increases with increasing intra class correlation coefficient and/or overall sample size. Furthermore, multilevel models where the between and within cluster components of first-level covariates are distinguished perform significantly better than both multilevel models where the two effects are set to be equal and the fixed effect models

Indagine sismica a riflessione ad alta risoluzione con sorgente vibratoria Ivi-MiniVib svolta nel comune di Piedimonte Etneo (CT) in località Presa.

Il presente lavoro ha avuto come obiettivo lo studio dettagliato della porzione superficiale (0-500 metri di profondità) della faglia Pernicana attraverso l’acquisizione e l’elaborazione di dati sismici a riflessione e rifrazione ad alta risoluzione. E’ stato acquisito un profilo sismico di 715 metri, in località Presa nel comune di Piedimonte Etneo (CT), mediante l’impiego di una sorgente sismica vibratoria ad alta risoluzione. Questo sito è stato scelto in quanto è attraversato dalla rottura superficiale indotta dalla faglia Pernicana

The Vallo di Diano Range-Bounding Fault-System (Southern Italy): New Evidence of Recent Activity From High-Resolution Seismic Profiling

The Vallo di Diano is the largest intermountain basin in the Southern Apennines (Italy). The basin evolution was controlled by the Quaternary activity of a range-bounding, SW-dipping normal fault system located to the east (Vallo di Diano Fault System, VDFS). Geological and oil industry data define the sin-sedimentary activity of the VDFS up to the Middle Pleistocene. However, commercial profiles do not resolve the shallower, eastern portion of the basin, due to strong lateral heterogeneities and unfavourable surface conditions. Therefore, Late Pleistocene-Holocene activity of the VDFS and its seismogenic potential are still uncertain. To better constrain the shallow structure of the basin, we performed four high-resolution seismic surveys, along its eastern side, where slope breccias and fans cover the Mesozoic carbonate bedrock and bury the VDFS. We also investigated some NW-trending flexures affecting Late Pleistocene fans, that we had previously detected and dubitatively ascribed to recent faulting. Seismic data were acquired with a dense wide-aperture geometry. Two high-resolution (HR) NE-trending profiles, about 1.5 km long, were collected using respectively 5 m and 10 m spaced receivers and sources. Two very high-resolution (VHR) NE-trending profiles, 400 and 350 m long, with densely spaced sources (4 m) and receivers (2 m) were also collected. HR profiling was aimed at imaging alluvial fan thickness and morphology of the underlying carbonate bedrock. VHR surveys targeted the flexures and their possible origin. All lines were acquired with a HR vibroseis source, except for the shortest profile, where we used a buffalo-gun, better suited for very near-surface imaging (z < 50 m depth). Seismic imaging consists of reflectivity images obtained by CDP-processing of reflection data complemented by Vp images obtained by multi-scale seismic tomography. The stack sections illuminated the basin down to 0.4-0.5 s TWT and reveal an array of high-angle, generally SW-dipping faults dissecting the bedrock and the alluvial fans. Faulting created accommodation space in the hanging-wall and displaced the different fan generations. Clear reflection truncations in the stack-sections correspond to significant Vp lateral changes in the tomographic images. VHR tomography is well defined along the shortest line down to 40 m depth, where two steps within slope breccias are visible. Moreover, two low-velocity wedges (colluvial packages) are imaged in the near surface (5-20 m depth). These data support recent faulting consistently with surface geomorphic features. We interpret these fault structures as splays of the range bounding master fault. Comparison with commercial reflection profiles nearby reveals a great improvement in seismic imaging achieved by HR surveys, which allow a detailed seismostratigraphic analysis of the basin.UnpublishedSan Francisco (CA), Moscone West, Howard Street3.2. Tettonica attivaope

The Vallo di Diano Range-Bounding Fault-System (Southern Italy): New Evidence of Recent Activity From High-Resolution Seismic Profiling

The Vallo di Diano is the largest intermountain basin in the Southern Apennines (Italy). The basin evolution was controlled by the Quaternary activity of a range-bounding, SW-dipping normal fault system located to the east (Vallo di Diano Fault System, VDFS). Geological and oil industry data define the sin-sedimentary activity of the VDFS up to the Middle Pleistocene. However, commercial profiles do not resolve the shallower, eastern portion of the basin, due to strong lateral heterogeneities and unfavourable surface conditions. Therefore, Late Pleistocene-Holocene activity of the VDFS and its seismogenic potential are still uncertain. To better constrain the shallow structure of the basin, we performed four high-resolution seismic surveys, along its eastern side, where slope breccias and fans cover the Mesozoic carbonate bedrock and bury the VDFS. We also investigated some NW-trending flexures affecting Late Pleistocene fans, that we had previously detected and dubitatively ascribed to recent faulting. Seismic data were acquired with a dense wide-aperture geometry. Two high-resolution (HR) NE-trending profiles, about 1.5 km long, were collected using respectively 5 m and 10 m spaced receivers and sources. Two very high-resolution (VHR) NE-trending profiles, 400 and 350 m long, with densely spaced sources (4 m) and receivers (2 m) were also collected. HR profiling was aimed at imaging alluvial fan thickness and morphology of the underlying carbonate bedrock. VHR surveys targeted the flexures and their possible origin. All lines were acquired with a HR vibroseis source, except for the shortest profile, where we used a buffalo-gun, better suited for very near-surface imaging (z < 50 m depth). Seismic imaging consists of reflectivity images obtained by CDP-processing of reflection data complemented by Vp images obtained by multi-scale seismic tomography. The stack sections illuminated the basin down to 0.4-0.5 s TWT and reveal an array of high-angle, generally SW-dipping faults dissecting the bedrock and the alluvial fans. Faulting created accommodation space in the hanging-wall and displaced the different fan generations. Clear reflection truncations in the stack-sections correspond to significant Vp lateral changes in the tomographic images. VHR tomography is well defined along the shortest line down to 40 m depth, where two steps within slope breccias are visible. Moreover, two low-velocity wedges (colluvial packages) are imaged in the near surface (5-20 m depth). These data support recent faulting consistently with surface geomorphic features. We interpret these fault structures as splays of the range bounding master fault. Comparison with commercial reflection profiles nearby reveals a great improvement in seismic imaging achieved by HR surveys, which allow a detailed seismostratigraphic analysis of the basin

La valutazione dei servizi di supporto alla didattica

Nel sistema universitario gli studenti rappresentano gli utenti e gli attori principali dei servizi offerti dagli Atenei. Nella nota si procede ad una valutazione dell‟eventuale impatto sia del trasferimento di tre facoltà dell‟Ateneo fiorentino in un‟unica struttura sia dell‟entrata in vigore della riforma dei cicli e degli ordinamenti didattici del sistema universitario italiano sulla qualità dei servizi offerti così come viene percepita dagli studenti. A tal fine sono stati analizzati i dati dell‟indagine relativa ai Servizi di Supporto alla Didattica presenti nel Polo delle Scienze Sociali predisposta dal Nucleo di Valutazione Interna dell‟Ateneo fiorentino. Per pervenire ad una “misura” della qualità percepita relativamente ad alcuni dei servizi indagati (Didattica e Biblioteca del Polo), sono state impiegate tecniche proprie della statistica descrittiva. Inoltre, ai fini dell‟analisi di quelle che possono essere le determinanti della soddisfazione, si è proceduto alla definizione e alla successiva stima di uno specifico modello di Customer Satisfaction (CS) relativamente al servizio della Biblioteca

Campagna d’acquisizione di dati sismici a riflessione e rifrazione ad alta risoluzione con sorgente vibratoria Ivi-MiniVib svolta nel comune di Parcines (BZ).

Il presente lavoro ha avuto come obiettivo lo studio dettagliato della porzione superficiale (0-1000 metri di profondità) di un settore della Val Venosta, Alto Adige Occidentale, al fine di caratterizzare, in termini di spessori e di velocità di propagazione, le spesse coltri dei sedimenti di conoide che costituiscono i terreni affioranti della zona. L’indagine è stata tarata anche al fine di ricostruire la geometria e la profondità del substrato roccioso. Sono stati acquisiti due profili sismici a riflessione ad alta risoluzione che coprono l’intera ampiezza della valle, per un totale di 2050 metri di stendimento. I dati sono stati registrati impiegando una sorgente sismica vibratoria ad alta risoluzione (Ivi-MiniVib®)

Ranking of Universities Effectiveness Using Multilevel Linear Regression: Robustness to Model Misspecifications

In the educational field one aim of the research is to evaluate the school or university effectiveness. In particular, the researcher is usually interested in obtaining a rank of the institutions and multilevel modeling is a widely applied tool to achieve this goal. This paper focuses on the evaluation of the robustness of the ranking obtained with multilevel models in case of different misspecifications of the model. The analyses are carried out through Monte Carlo simulations